The elastomer, which is soft and exhibits rubber elasticity, has been used in a wide range of applications, such as a sealing material, an absorber and the like. However, when the elastomer is exposed to acid, alkali, ultraviolet rays or the like, its molecular weight is lowered by, for example, a depolymerization reaction caused by hydrolysis or the like, with the result that its physical properties deteriorate. Moreover, depending on applications, higher mechanical strength (tearing strength, Young's Modulus, or the like), conductive characteristic, and the like are required.
By combining the elastomer with a filler having a nano-scale diameter, such as, for example, carbon nanotubes (hereinafter, referred to also as CNT) as a composite component, attempts have been made so as to improve the mechanical strength, conductive characteristic and the like. For example, in Japanese Patent Publication No. 5374047, a carbon fiber composite material has been reported on which an interface phase that is considered to be an aggregate of molecules of a fluorine-containing elastomer adsorbed on the surface of a vapor-growth carbon fibers that are similar to bound rubber formed on the periphery of carbon black when dispersing multi-layer carbon nanotubes in a binary or ternary synthetic rubber containing fluorine atoms in its molecule and kneading a fluorine-containing elastomer and carbon black. Japanese Patent Publication No. 5374047 has described that as the amount of the vapor-growth carbon fiber increases, the interface phases are mutually chain-connected to one another to form minute cells and in the case when the multi-walled carbon nanotubes in the carbon fiber composite material are set to an optimal ratio, invasion of oxygen into the cells of the carbon fiber composite material is reduced by the chain-connected interface phases so that the material becomes less susceptible to thermal deterioration and makes it possible to maintain high elastic modulus.
Moreover, Japanese Patent Publication No. 5197288 has reported a fiber composite material in which single-walled carbon nanotubes or multi-walled carbon nanotubes and natural fibers or metal fibers are dispersed in an elastomer. Japanese Patent Publication No. 5197288 has described that by surrounding an elastomer forming a matrix with fibers and carbon nanofibers, a restraining region is formed and the mobility of elastomer molecules restrained by the fibers and carbon nanofibers becomes lower than that in the case of being not restrained by the fibers and carbon nanofibers.